Abstract

PURPOSE: Prednisolone has been widely used due to its relatively short pituitary inhibition and its moderate potency. Exercise is one of the non-pharmacological interventions for glucocorticoid- induced osteoporosis prevention. However, the effects of exercise on the pharmacokinetics of prednisolone were unclear. The purpose of this study was to evaluate the effects of sub-maximal exercise on the pharmacokinetics of prednisolone. METHODS: A randomized, double-blind, cross-over experimental design was used. Subjects needed to undertake two trials: a non-exercise trial (NE) and an exercise trial (E). After the first blood sampling, the subjects consumed 5mg of prednisolone with 100mL of water and then took a rest for 30 min. In the E trial, subjects cycled at 70% VO2max intensity until exhaustion. When subjects underwent the NE trial, they remained seated for the duration of the experiment. Serial blood samples were collected at 0.25, 0.5, 0.75, 1, 1.25, 1.5, 2, 3, 4, 5, 6, 8, 10 and 12h after prednisolone administration. Prednisolone and cortisol concentration were analyzed with a validated high performance liquid chromatographic method. RESULTS: This study indicated that the maximum concentration of the E trial was significantly lower than the NE trial (p<0.05). However, the area under the serum concentration-time, the time to half life concentration, the time-averaged total body clearance, and the apparent volume of the distribution showed no significant difference between two trials. The mean of cortisol concentration in E trail increased 8 ±8.5 %. CONCLUSION: The results suggested that sub-maximal exercise altered the prednisolone absorption pattern.